[EricH]

I think that you should check the FTC Q&A forums. [friendly reminder] Nothing said here is official, or can be interpreted as official.[/reminder]

That said, you'd have better chances with the argument that it is a "compatible mechanical fastener" based on FTC <R5-C-13>. Remember, the FTC game designers may disagree with me on this, so you'll want to ask them.

Edit: When I checked the FTC Q&A, I couldn't find anything specifically on staples, but I got the impression that they would not be allowed unless you did in fact make your own from the aluminum sheet. However, nobody has asked yet.